Transforming growth factor alpha treatment alters intracellular calcium levels in hair cells and protects them from ototoxic damage in vitro

To determine if transforming growth factor alpha (TGFα) pretreatment protects hair cells from aminoglycoside induced injury by modifying their intracellular calcium concentration, we assayed hair cell calcium levels in organ of Corti explants both before and after aminoglycoside (i.e. neomycin, 10⁻³M) exposure either with or without growth factor pretreatment. After TGFα (500ng/ml) treatment, the intracellular calcium level of hair cells showed a five-fold increase as compared to the levels observed in the hair cells of control cultures. After ototoxin exposure, calcium levels in hair cells of control explants showed an increase relative to their baseline levels, while in the presence of growth factors pretreatment, hair cells showed a relative reduction in calcium levels. Pretreatment of organ of Corti explants afforded significant protection of hair cell stereocilia bundle morphology from ototoxic damage when compared to explants exposed to ototoxin alone. This study correlates a rise in hair cell calcium levels with the otoprotection of hair cells by TGFα in organ of Corti explants.     

Morphometrically estimated variation in nuclear size

Summary At present there are several grading systems for prostatic carcinoma. Most are difficult to reproduce. An objective method of grading seems to be necessary and could make comparisons between various groups of patients easier and grading more reliable.In the present study morphometrically estimated nuclear size and variation in nuclear size are matched with the survival rates of 207 patients who underwent total perineal prostatetomy for cancer. On the basis of morphometrically estimated variation in nuclear size the patients could be divided into two groups with significantly differing survival rates. In this way it was possible to split the group of patients with grade 2 carcinoma (Mostofi's grading system) into two groups of patients with significantly different survival rates. The survival rates in these two groups did not differ significantly from those in the patients with Grade 1 and Grade 3 tumors respectively.The results are discussed in the light of the recent literature on the subject. Morphometry seems to be a valuable tool in grading prostatic cancer.     

Variation of prostate-specific antigen expression in different tumour growth patterns present in prostatectomy specimens

Summary A series of 55 randomly chosen radical prostatectomy specimens was analyzed for expression of prostate-specific antigen (PSA) by immunohistochemical techniques. Tissue sections were selected in such a manner that in addition to glandular benign prostatic hyperplasia (BPH), one or more different prostatic tumour growth patterns were present. Four monoclonal antibodies, directed against three different PSA epitopes, and one polyclonal anti-PSA antiserum were used. Expression of PSA was compared with that of prostate-specific acid phosphatase (PAP), recognized by two different polyclonal antisera. A critical dilution aimed at a maximum of staining intensity on BPH tissue sections was chosen for all antibodies. Anti-PSA and anti-PAP antisera stained essentially all BPH samples (over 90%). Irrespective of the nature of the antibodies used, PSA expression was found to be decreased in prostatic carcinoma. A clear cut relationship was found between immunoreactivity for PSA and the degree of differentiation of the tumour area. Under the experimental conditions used the PSA monoclonal antibodies stained only 1 out of 10 undifferentiated carcinomas, whereas 50% to 70% of the well- and moderately-differentiated carcinomas showed immunoreactivity. This correlation was less pronounced with the PAP staining pattern. If the PSA antibody titer was raised the percentage of clearly staining undifferentiated carcinomas could be considerably increased (up to 60%–100%), indicating that PSA expression is not absent, but lowered in most (if not all) undifferentiated carcinomas.     

Onychomycoses due to Microascus cirrosus (syn. M. desmosporus)

Microascus cirrosus is very rarely the aetiological agent of onychomycosis. We report two additional cases of toenail infections caused by this fungus.     

Inhibition of Complement Regulation Is Key to the Pathogenesis of Active Heymann Nephritis

Crry (complement receptor 1–related protein/gene y) is a key cellular complement regulator in rodents. It is also present in Fx1A, the renal tubular preparation used to immunize rats to induce active Heymann nephritis (HN), a model of membranous nephropathy. We hypothesized that rats immunized with anti-Fx1A develop autoantibodies (auto-Abs) to Crry as well as to the megalin-containing HN antigenic complex, and that anti-Crry Abs promote the development of injury in HN by neutralizing the complement regulatory activity of Crry. Rats immunized with Fx1A lacking Crry remained free of proteinuria and glomerular deposits of C3 during a 10-wk follow-up despite typical granular immunoglobulin (Ig)G deposits in glomeruli. Anti-Fx1A auto-Abs were present in their sera at levels that were not different from sera pooled from proteinuric rats with HN induced with nephritogenic Fx1A. Passive administration of sheep anti-Crry Abs to rats immunized with Crry-deficient Fx1A led to proteinuria and glomerular C3 deposition, which were not seen in such rats injected with preimmune IgG, nor in rats with collagen-induced arthritis injected with anti-Crry IgG. To directly examine the role of Crry in HN, rats were immunized with Crry-deficient Fx1A reconstituted with rCrry. This led to typical HN, with 8 out of 15 rats developing proteinuria within 14 wk. Moreover, the extent of glomerular C3 deposition correlated with proteinuria, and anti-Crry Abs were present in glomerular eluates. Thus, Crry is a key nephritogenic immunogen in Fx1A. Formation of neutralizing auto-Abs to Crry impairs its function, leading to unrestricted complement activation by Abs reactive with the HN antigenic complex on the epithelial cell surface.     

Cell proliferation in human tumours growing in nude mice: renal cell carcinomas,larynx and hypopharynx carcinomas

Summary Cell proliferation of 51 human renal cell carcinomas and 9 larynx and hypopharynx carcinomas has been studied in vitro and using xenotransplants. The proliferative activity ([³H]thymidine labelling index) increases during the first passages in nude mice and then remains almost constant throughout subsequent passages. A comparison of cell kinetic parameters of 8 human renal cell carcinomas, 1 hypopharynx and 2 larynx carcinomas, with data of xenografts and of human tumours in situ published up to now, shows that the cell kinetic parameters of human tumour xenografts presently studied range between those of human tumours in situ and those of autochthonous or transplantable mouse tumours. S-phase durations and potential doubling times are considerably shorter in xenotransplants than in human tumours in situ, whereas the cycle time is about the same. This means that the growth fraction increases considerably after xenotransplantation. This change of human tumour cell proliferation after transplantation into nude mice should be kept in mind if one wishes to draw conclusions from the nude mouse model on conditions in human beings, particularly with respect to therapeutic regimens, which are frequently tested in the nude mouse model.Abbreviations used RCC renal cell carcinoma - HPC larynx or hypopharynx carcinoma - LI labelling index - PLM percentage of labelled mitoses - t _s S-phase duration - t _c cycle time - t _pot potential doubling time This work was supported by the Deutsche Forschungsgemeinschaft (Ma 876/2-1)     

Synthetic Colloids Attenuate Leukocyte-Endothelial Interactions by Inhibition of Integrin Function

Background: It has been suspected that synthetic colloids may interfere with leukocyte adhesion by down-regulation of endothelial cell adhesion molecules. Although inhibition of endothelial inflammation might reduce leukocyte-related tissue injury, the same mechanism may be detrimental for host defense during severe infection. Regarding the widespread use of colloids, the authors performed a laboratory investigation to determine the mechanisms by which synthetic colloids interfere with leukocyte-endothelial interactions.

Methods: Adhesion molecule expression on native and cytokine-activated endothelium from umbilical veins was measured after pretreatment with gelatin and various preparations of dextran or hydroxyethyl starch. Inhibition of neutrophil adhesion to activated endothelium was examined in a flow chamber by perfusion of untreated and colloid-treated neutrophils over colloid-pretreated endothelium at 2 dyn/cm2. Comparisons were made between untreated controls, colloid-pretreated endothelium, and colloid-cotreated neutrophils.

Results: Intercellular adhesion molecule 1, vascular cell adhesion molecule 1, E-selectin, and P-selectin were not attenuated by any colloid. Accordingly, colloid pretreatment of endothelium alone did not reduce neutrophil adhesion. In contrast, when neutrophils were cotreated by addition of colloids to the perfusate immediately before perfusion, adhesion decreased by 31-51% (P < 0.05) regardless of the colloid type. As indicated by the twofold increased rolling fractions, this reduction was due to an inhibition of neutrophil integrins.     

Efficacy of a single pretransplant donor-specific transfusion and cyclosporin A administered 24 to 48 hours before one-haplotype-mismatched living related donor kidney transplant.

During the 7-year period from March 1984 to June 1991, 86 haploidentical living related kidney recipients were entered into one of three donor-specific transfusion (DST) and cyclosporine treatment protocols: (1) Multiple pretransplant DSTs with cyclosporine begun after transplant, n = 34; (2) Multiple pretransplant DSTs with cyclosporine begun pretransplant, n = 31; and (3) a single DST 24 to 48 hours before transplant with intravenous cyclosporine initiated after the transfusion, n = 21. Triple immunosuppression (prednisone, azathioprine, and cyclosporine) was continued in all groups after transplant. The 1-year patient (97%, 97%, and 93%, p = not significant) and graft (91%, 90%, and 87%, p = not significant) survival were similar for the three groups. No differences were seen in the incidence of rejection at 1 year (61%, 45%, and 60%, p = not significant) or in the incidence of infectious complications (26%, 42%, and 47%, p = not significant). It is concluded that a single DST given 24 to 48 hours before operation followed by pretransplant cyclosporine is as effective as classic DST conditioning of recipients using either pretransplant or post-transplant cyclosporine. The single DST protocol has the advantage of not eliminating any donors because of sensitization and was less costly and easier to administer.